I have solved this. I found on the Internet, how to update the repository.
curl -s https://packages.microsoft.com/config/rhel/7/prod.repo | sudo tee /etc/yum.repos.d/msprod.repo
Then I was able to update unixODBC to the latest version 2.3.7
I am currently using FreeTDS to connect to Microsoft SQL Server and planning to switch to the Microsoft SQLSRV driver, which requires the lastest version of unixODBC for connection pooling support. The database is used in AGI to get and update external data.